Dispositions - Additional Information (Detail) (USD $)	9 Months Ended		3 Months Ended			1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013 Azeri-Chirag-Guneshli (ACG) fields [Member]	Mar. 31, 2013 Baku-Tbilisi-Ceyhan (BTC) pipeline [Member]	Mar. 31, 2013 Baku-Tbilisi-Ceyhan pipeline and Azeri-Chirag-Guneshli fields [Member]	Jan. 31, 2013 Beryl Fields and Scottish Area Gas Evacuation System (SAGE) [Member]	Jan. 31, 2013 Beryl Fields [Member]	Jan. 31, 2012 Snohvit [Member]	Apr. 30, 2013 Samara-Nafta [Member]	Sep. 30, 2012 Schiehallion Field [Member]
Dispositions [Abstract]
Cash proceeds from sale of subsidiary									$ 2,100,000,000
Corporation's proportionate interest in oil and gas assets (in percentage)			3.00%	2.00%			22.00%	3.00%	90.00%	16.00%
Cash proceeds from asset sales	3,802,000,000	656,000,000			884,000,000	442,000,000		132,000,000	1,900,000,000	524,000,000
Gain on asset sale, after-tax					360,000,000	323,000,000		36,000,000	1,119,000,000	349,000,000
Goodwill written off related to sale of business unit	339,000,000				52,000,000	48,000,000			148,000,000
Net gain on sale attributable to noncontrolling interest holder's share									168,000,000
Net gain on sale attributable to parent									951,000,000
Gain on asset sale, pre-tax						$ 328,000,000				$ 376,000,000